Daikin LREN8A7Y1B - Refrigerant piping length and height difference

15 | Piping installation
Installer and user reference guide
73
LREN8~12A7 + LRNUN5A7
CO₂ ZEAS outdoor unit and capacity up unit
4P704142-1 – 2022.08
NOTICE
Foreign materials inside pipes are NOT allowed (including oils for fabrication).
NOTICE
The piping and other pressure-containing parts shall be suitable for refrigerant and
oil. Use K65 (or equivalent) copper-iron alloy tube system for high-pressure
applications with a working pressure of 90bar gauge at the refrigeration side.
NOTICE
NEVER use standard hoses and manometers. Use ONLY equipment that is designed
to use with R744.
NOTICE
If the ability to close the stop valves for field piping is wanted, the installer MUST
install a pressure relief valve on the liquid piping between the outdoor unit and the
refrigeration indoor units.
INFORMATION
Also read the precautions and requirements in the "2 General safety
precautions"[46].
15.1.2 Refrigerant piping material
▪ Piping material: K65 and equivalent piping, maximum system operation pressure
in field piping is 90bar gauge.
▪ Piping temper grade and thickness:
Piping type Outer
diameter (Ø)
Temper
grade
Thickness (t)
(a)
Design
pressure
Liquid
piping
15.9mm
(5/8")
R300 1.05mm 120 bar
gauge
t
Ø
Gas piping 22.2mm
(7/8")
R300 1.50mm 120 bar
gauge
(a)
Depending on the applicable legislation and the maximum working pressure of the unit
(see "PS High" on the unit name plate), larger piping thickness might be required.
15.1.3 Refrigerant piping length and height difference
Requirements and limits
The piping lengths and height differences must comply with the following
requirements. For an example, see "15.1.4To select the piping size"[475].
Requirement Limit
LREN* LREN* + LRNUN5*
Maximum piping length
Examples:
▪ A+B+C+D+(E or F)
(a)
≤Limit
▪ a+b+c+d+(e or f)
(a)
≤Limit
Low temperature: 100m
(b)
Medium temperature: 130m
(b)